1. Field of the Invention
The present invention relates to a technology for controlling a variable valve actuation device which variably changes a phase of the center of an operating angle of an intake valve, and lift characteristics of the intake valve.
2. Description of the Related Art
Japanese Unexamined Patent Publication No. 11-210510 discloses a technology for learning an output value of a lift sensor at a fully opened position of an engine valve and a fully closed position thereof, in a variable valve actuation device which operates the engine valve to open or close by means of a solenoid coil.
Further, Japanese Unexamined Patent publication No. 11-82073 discloses a technology for learning the most retarded angle position of valve timing for each operating region of an engine, in a variable valve actuation device which adjusts a phase difference of a camshaft to a crankshaft.
According to the above conventional technologies, the fully closed position of the engine valve and the fully opened position thereof or the most retarded angle position of the valve timing, can be accurately detected.
However, it is impossible to detect the deviation of the fully closed position of the engine valve or the fully opened position thereof from a desired position, or the deviation of the most retarded angle position of the valve timing from a desired position.
Accordingly, in the case where the variable valve actuation device is provided in each bank in a V-type engine, a difference in intake air quantity may occur between each bank, to thereby reduce the engine rotation stability or the silence of the engine.
Therefore, it is desired that the variable valve actuation device on each bank is corrected based on the difference in intake air quantity between each bank.
However, in an engine provided with a variable valve lift mechanism which varies lift characteristics (a lift amount and/or an operating angle) of an intake valve, and a variable valve timing mechanism which changes a phase of an intake camshaft relative to a crankshaft, an intake air quantity is changed by both of an influence of the lift characteristics of the intake valve and an influence of a phase of the center of the operating angle of the intake valve.
Therefore, there is a problem in that the variable valve lift mechanism and the variable valve timing mechanism cannot be corrected appropriately.